Our finding of a positive association between BMI and overall ovarian cancer risk in BRCA1 and BRCA2 mutation carriers is corroborated by several prior studies in the general population.12,14,15,33 One MR analysis using 77 BMI-associated SNPs, conducted in the general population, found that each 1-standard deviation (SD) increment in genetically-predicted adult BMI corresponded to an odds ratio (OR) of 1.35 (95% CI: 1.05–1.72).34 We found that 5-kg/m2 (about 1 SD) increment in genetically predicted BMI was associated with an HR = 1.10 (95% CI: 0.86–1.42) in mutation carriers. The gene discussed is BRCA2; the disease is ovarian carcinoma.